In recent years there has been increasing concern with reducing injuries that occur when children fall from playground equipment and strike the underlying surface. Hard surfacing materials such as asphalt and concrete do not provide adequate injury protection from falls and are therefore generally unsuitable for use under and around playground equipment. Other surfacing materials commonly used around playground equipment are wood chips, bark chips and sand. These particulate materials require continuous maintenance and their cushioning potential depends upon the air trapped within and between the individual particles. Thus, as the materials decompose or become pulverized over a period of time, they tend to lose their cushioning effect. In the case of sand, moisture tends to increase the cohesiveness of the sand and therefore reduce its cushioning effect.
One proposed solution to the aforementioned problems is to construct a recreation surface using a plurality of tiles made of rubber crumbs bound together with a suitable binding material and molded into generally square tiles. U.S. Pat. Nos. 4,848,058 and 4,921,741 disclose such tiles and means for interlocking and fastening the tiles, respectively. An array of the bonded rubber crumb (BRC) tiles possesses desirable shock attenuation characteristics. The tiles disclosed in the aforementioned patents may have a solid parallelepiped structure, or they may have "dimples" in the bottom surface thereof or "cores" extending transversely through the body of the tile to enhance the shock attenuation characteristic of the tile. Tiles having these various configurations may present certain manufacturing difficulties.
One known BRC-type tile has an upper tile region of uniform thickness from which extend downwardly a plurality of legs of substantially square cross-section throughout their length. The tile, at its perimeter, has a plurality of perimeter legs which have a smaller cross-sectional area than the legs in the central region, with the exception of L-shaped perimeter legs located at the corners of the tile. Although these prior art BRC tiles provide significant improvements over other known prior art BRC tiles, their shock attenuation characteristics are not ideal, and their resistance to removal when adhered to an underlying support surface leaves room for improvement.